Slit Design for the Thermal Flying Height Control Slider

2013 ◽  
Author(s):  
Hui Li ◽  
Shengnan Shen
Keyword(s):  
Magnetic Recording ◽  
Thermal Structure ◽  
Areal Density ◽  
Thermal Actuator ◽  
Flying Height ◽  
Air Bearing ◽  
Disk Drives ◽  
Height Control ◽  
Thermal Flying Height Control ◽  
Structure Simulation

Thermal flying height control (TFC) has recently been implemented in magnetic recording disk drives to reduce the flying height at the read/write element for high areal density magnetic recording. In this work, we propose a novel thermal flying height control slider, by designing a slit near the thermal heater in the slider. The thermal-structure simulation coupled with air bearing simulation is used to simulate the actuation by the thermal actuator, as well as the effects on flying performance of slider being actuated.

Contact and temperature rise of thermal flying height control sliders in hard disk drives

2012 ◽  
Vol 18 (9-10) ◽  
pp. 1693-1701 ◽  
Author(s):  
Liane Matthes ◽  
Uwe Boettcher ◽  
Bernhard Knigge ◽  
Raymond de Callafon ◽  
Frank E. Talke
Keyword(s):  
Temperature Rise ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Flying Height ◽  
Disk Drives ◽  
Height Control ◽  
Thermal Flying Height Control

Design and Dynamics of Flying Height Control Slider With Piezoelectric Nanoactuator in Hard Disk Drives

2006 ◽  
Vol 129 (1) ◽  
pp. 161-170 ◽  
Author(s):  
Jia-Yang Juang ◽  
David B. Bogy ◽  
C. Singh Bhatia
Keyword(s):  
Numerical Study ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Areal Density ◽  
Flying Height ◽  
Air Bearing ◽  
Disk Drives ◽  
Adhesion Forces ◽  
Surface Design ◽  
Ultrahigh Density

To achieve the areal density goal in hard disk drives of 1Tbit∕in.2 the minimum physical spacing or flying height (FH) between the read/write element and disk must be reduced to ∼2nm. A brief review of several FH adjustment schemes is first presented and discussed. Previous research showed that the actuation efficiency (defined as the ratio of the FH reduction to the stroke) was low due to the significant air bearing coupling. In this paper, an air bearing surface design, Slider B, for a FH control slider with a piezoelectric nanoactuator is proposed to achieve virtually 100% efficiency and to increase dynamics stability by minimizing the nanoscale adhesion forces. A numerical study was conducted to investigate both the static and dynamic performances of the Slider B, such as uniformity of gap FH with near-zero roll over the entire disk, ultrahigh roll stiffness and damping, low nanoscale adhesion forces, uniform FH track-seeking motion, dynamic load/unload, and FH modulation. Slider B was found to exhibit an overall enhancement in performance, stability, and reliability in ultrahigh density magnetic recording.

Air Bearing Pushback in Heat Assisted Magnetic Recording

2019 ◽  
Author(s):  
Shaomin Xiong ◽  
Robert Smith ◽  
Chanh Nguyen ◽  
Youfeng Zhang ◽  
Yeoungchin Yoon
Keyword(s):  
Magnetic Recording ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Disk Drive ◽  
Flying Height ◽  
Air Bearing ◽  
Magnetic Media ◽  
Heat Assisted Magnetic Recording ◽  
Height Control ◽  
Different Dimensions

Abstract The air bearing surface is critical to the spacing control in current hard disk drives (HDDs). Thermal protrusions, including thermal flying height control (TFC) and writer coil protrusion, drive the reader/writer elements closer to the magnetic media. The spacing control actuation efficiency depends on the air bearing push back response after the TFC or writer protrudes. In the next generation hard disk drive technology, heat assisted magnetic recording (HAMR), laser induced protrusions further complicate the spacing control. The laser induced protrusions, such as the localized NFT protrusion and a wider change of the crown and camber, have very different dimensions and transient characteristics than the traditional TFC and writer protrusion. The dimension of the NFT protrusion is relatively smaller, and the transient is much faster than the TFC protrusion. However, it is found that the NFT protrusion is large enough to generate an air bearing push back effect, which changes the read and write spacing when the laser is powered on. To accurately control spacing in HAMR, this push back effect has to be taken into account.

Investigation of Head Burnishing of Thermal Flying Height Control Sliders

2013 ◽  
Author(s):  
Liane Matthes ◽  
Ralf Brunner ◽  
Bernhard Knigge ◽  
Frank E. Talke
Keyword(s):  
Thin Film ◽  
Surface Roughness ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Flying Height ◽  
Disk Drives ◽  
Lubricant Transfer ◽  
Height Control ◽  
Thermal Flying Height Control ◽  
Disk Spacing

The head-disk spacing in current hard disk drives is approximately 1–2 nm. This distance is on the same order as the peak to valley surface roughness of a typical thin film disk. If one attempts to reduce the head-disk spacing even more, intermittent contacts between the slider and the disk are more likely to occur. Intermittent contacts are undesirable since they can result in slider and disk wear, lubricant transfer or degradation of the read and write elements.

Flying Clearance Distribution With Thermal Flying Height Control in Hard Disk Drives

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
Sung-Chang Lee ◽  
George W. Tyndall ◽  
Mike Suk
Keyword(s):  
Temperature Compensation ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Flying Height ◽  
Disk Drives ◽  
Disk Interface ◽  
Height Control ◽  
Thermal Flying Height Control ◽  
Height Change ◽  
The Individual

Flying clearance distribution with thermal flying height control (or thermomechanical actuation) is characterized. Especially, factors contributing to variation in the flying clearance are identified based on the flying height change profiles taken from the burn-in process of hard disk drives and Gage R&R (repeatability and reproducibility) test of touch down repeatability. In addition, the effect of static temperature compensation scheme on the flying clearance distribution is investigated, and the disadvantage of static adaptation to temperature change is identified. In order to avoid early catastrophic head-disk interface failures due to poor static temperature compensation, dynamic clearance adjustment is necessary whenever environmental condition changes. Otherwise, static temperature compensation using the individual temperature sensitivity values of each head needs to be applied.

Nano Wear of Thermal Flying Height Control Sliders

2014 ◽  
Author(s):  
Andreas Hegetschweiler ◽  
Liane Matthes ◽  
Frank E. Talke
Keyword(s):  
Hard Disk Drives ◽  
Disk Surface ◽  
Flying Height ◽  
Disk Drives ◽  
Heater Power ◽  
Heater Element ◽  
Height Control ◽  
Thermal Flying Height Control ◽  
Intermittent Contact ◽  
Peak Value

To increase the storage density in hard disk drives (HDDs), the clearance between the read/write head and the disk has to be reduced. In current HDDs, the flying height of the slider is about 1–2 nm, which is on the same order as the peak to peak value of the disk surface roughness. As a consequence, intermittent contact between the slider and the disk might occur. Intermittent head-disk contacts are undesirable since they can result in wear of the slider or lubricant transfer [1]–[5]. To achieve flying-heights of 1–2 nm, thermal flying height control (TFC) sliders have been introduced in HDDs [6]. TFC sliders contain a small heater element close to the read and write element. Energizing the heater element results in thermal expansion of the slider body and a thermal protrusion is formed. An increase in heater power increases this protrusion, thereby bringing the read and write element closer to the disk (Fig. 1).

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